JPS5838459A - Manufacture of plate for enclosed alkaline battery - Google Patents

Abstract

PURPOSE:To produce a plate having the improved charging efficiency under the high temperature with minute current, by immersing a Ni anode plate in LiOH water solution under the reduced pressure. CONSTITUTION:The carbonyl Ni powder is sintered to produce a porous thin Ni plate to be employed as the anode plate, then it is impregnated with the nickel nitrate and electrolitically reduced in the alkali water solution to produce the nickel hydroxide. Said process is repeated to maintain the predetermined amount of active substance then it is formed in NaOH. After the formation, the water washed and dried Ni anode plate is immersed in the water solution where LiOH is dissolved from 6wt% to the saturation under the reduced pressure lower than 400mm.Hg and after taking out it is water washed and dried. When charging the enclosed alkaline battery employing this anode plate with the minute current of 1/25-1/30CmA under the high temperature of 40-50 deg.C, the charging efficiency (discharge amount/charge amount) higher than 70% is exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for manufacturing electrode plates for sealed alkaline storage batteries, particularly nickel anode plates.

The conventional manufacturing method for anode plates for sealed alkaline storage batteries is to fill the active material, charge and discharge (oxidation-reduction) in an aqueous alkaline solution such as thorium hydroxide, wash with water, and dry. A sealed alkaline storage battery using an anode plate according to the method.

Crn (1m 1/25-c#FA to 1/30 A minute current.

When charging at a high temperature of 40 to 50°C, the charging efficiency (discharge jEL/charged amount) shows a low value of about 50%.

The purpose of the present invention is to improve the charging efficiency at low rate charging of I/25 to l/30 mmA at this high temperature m of 40 to 50°C.

In order to achieve the objective of the system, the present invention involves immersing a chemically formed nickel anode plate in an aqueous solution containing lithium hydroxide dissolved at a saturation level of 6% by weight or more and a decompressor of 400-Hg or less. It is something.

Next, one embodiment of the present invention will be described.

The anode plate is a nickel porous thin plate with a thickness of 11.1 m (pore diameter: I
Carbonyl nickel powder is sintered to form a substrate with a porosity of 80 to 9%. This substrate 1 is impregnated with nickel nitrate and electrolytically reduced in an alkaline aqueous solution to form nickel hydroxide.

This step is repeated 4 to 6 times to ensure a predetermined amount of active material. This is followed by chemical conversion in sodium hydroxide. After chemical formation, the washed and dried nickel anode plate was immersed in one 10% aqueous solution of lithium hydroxide to give 20 (ls+p)
Reduce the pressure to below Hg. After maintaining the reduced pressure state for 1 hour, the surface of the anode plate taken out was washed with running water for 5 minutes and dried to form a sealed alkaline crystal battery. The sealed alkaline storage battery we created complies with the JISC8705 standard (Kookeru NR).
-It is a cylindrical sealed nickel-cadmium storage battery that corresponds to the C type.

According to the present invention, lithium ions are forcibly introduced into the pores of the anode active material in a short time, as shown in Figure 1.
4008H with lithium hydroxide more than 6%
It is extremely effective in improving charging efficiency under atmospheric pressure of less than g. Note that FIG. 1 shows the charging efficiency at each reduced pressure at a lithium hydroxide concentration of 10%, and FIG. 2 shows the charging efficiency at each concentration at 2002 Hg. It can be seen that the effect of immersion under an atmospheric pressure of 200 degrees Hg when the lithium hydroxide concentration is 8 bars or more is almost constant.

Further, the charging and discharging conditions for the battery test were as shown below.

Crr+ Charge: +/25g1rAX24 hours m Discharge: ]cmA Final voltage per cell 1. The present invention has great value in that it can obtain electrode plates for sealed alkaline storage batteries with improved charging efficiency in a short time.

[Brief explanation of the drawing]

FIG. 1j shows the immersion of a nickel anode plate according to the invention in a 10 percent lithium hydroxide aqueous solution for one hour. A curve diagram showing the relationship between charging efficiency and atmospheric pressure. Figure 2 shows the immersion solution concentration and charging for a nickel anode plate immersed in a lithium hydroxide aqueous solution for 1 hour at an atmospheric pressure of 20 (1:mat:Hg). It is a curve diagram showing the relationship with efficiency. Patent applicant: Shin-Kobe Electric Co., Ltd.

Claims (1)

[Claims] 1. A method for producing an electrode plate for a sealed alkaline storage battery, which comprises immersing a nickel anode plate in an aqueous solution in which lithium hydroxide is dissolved to a disaturation level of 6% by weight or less under a pressure of 400 m-Hg or less.